1. Field of the Invention
The present invention relates to an ultra-high frequency partial discharge array sensor apparatus, and more particularly, to an ultra-high frequency partial discharge array sensor apparatus for detecting an electromagnetic wave partial discharge signal generated due to an internal defect of a high-voltage power apparatus such as a gas insulated switchgear, a power transformer, a reactor, or a high voltage rotating machine, in which a high sensitivity sensor for precisely measuring the amplitude of a discharge signal and a plurality of array sensors disposed at regular intervals are integrated as one body, thus measuring the position of an internal defect while detecting a discharge signal. Moreover, the ultra-high frequency partial discharge array sensor apparatus for a high-voltage power apparatus of the invention can eliminate the inconvenience of using a plurality of sensors which are to be installed on a housing of the high-voltage power apparatus to measuring a discharge position while detecting a partial discharge generated due to the internal defect and increase the accuracy of measuring the position of the internal defect by providing accurate coordinates of individual sensors.
2. Discussion of Related Art
An ultra-high frequency partial discharge sensor is usually used to detect an electromagnetic wave partial discharge signal generated due to an internal defect of a high-voltage power apparatus such as a gas insulated switchgear, a power transformer, a reactor, or a high-voltage rotating machine.
The ultra-high frequency partial discharge sensor has a structure in which a signal detected by one sensing unit with one sensor is transmitted to a measurement apparatus through a connector. In order to estimate the position where an electromagnetic wave partial discharge signal is generated in the high-voltage power apparatus using the ultra-high frequency partial discharge sensor having the above-described structure, at least two or three ultra-high frequency partial discharge sensors of the same type have to be installed. In particular, in order to measure the position where a partial discharge signal is generated in a reactor or a transformer with a three-dimensional structure, it is necessary to install three or four ultra-high frequency partial discharge sensors having the same structure and characteristic on a housing of the power apparatus.
After installing a plurality of ultra-high frequency partial discharge sensors on the housing of the power apparatus, the position where the partial discharge signal is generated is measured by a method such as time difference of arrival (TDOA).
However, when the plurality of ultra-high frequency partial discharge sensors are installed on the housing of the power apparatus, there is a problem in that relatively high cost and effort are required.
Further, in order to measure the positions using TDOA, it is necessary to simultaneously measure the accurate positions where the ultra-high frequency partial discharge sensors are installed. Therefore, there is a problem in that as the number of the ultra-high frequency partial discharge sensors increases, the errors in measuring the sensor positions increase, and thus computation errors also increase when computing the position of the internal discharge of the power apparatus.
Further, when the ultra-high frequency partial discharge sensors are installed in several locations, bending and length of signal connection lines increase, and thus many errors occur during arrival time measurement. Therefore, there is a problem in that the errors increase during position measurement using a signal arrival time.
As another technique for measuring the position where the partial discharge signal is generated in the power apparatus, a narrow band sensor in which a detection frequency band of the ultra-high frequency partial discharge sensor is narrow is used. In this case, since a signal corresponding to a detection band of the sensor is neither generated nor transmitted depending on the type of a discharge generated in the power apparatus or the position of an internal structure, it is difficult to detect the signal. Further, since a rising time of a detected signal is not fast, it is not easy to accurately measure a signal arrival time, and thus it is difficult to use the narrow band sensor to measure the internal position of the defect in the power apparatus.